This is the first complete translation into English of this Tibetan text, with reference to the Chinese version also, together with the informative commentary by the 8th century master Buddhaguhya. This text is of seminal importance for the history of Buddhist Tantra, especially as very little has been published concerning the origins of Tantra in India. During the last 30 years, there has been a revolution in the understanding and appreciation if the Buddhist Tantras in the west. Whereas in the past they were regarded with suspicion, they are now the focus of great interest among both the growing band of western Buddhists following the Tibetan tradtion and the smaller number of western academics specialising in Buddhist and related studies. However, this new interest in the Buddhist Tantras still have many limitations and unfortunately a detailed description of the development of tantric thought and practices is far from being complete. Moreover, almost without exception, present-day western writers have relied solely on Tibetan and Indic materials, especially the Anuttara-yoga tantras. But apart from these, there is a wealth of other tantric literature preserved in Tibetan sources and a vast amount of literature related to Tantric Buddhism available in Chinese, all awaiting detailed exploration and translation. Here, Stephen Hodge takes an important first step towards providing practicing Buddhists and Buddhist scholars access to this valuable material in an English translation.